Post by lucius1958 on Apr 14, 2015 23:04:21 GMT -5
There are a number of suppliers for belting, if you check the links given in the 'Web Resources' thread here, or the equivalent in the Talking Machine Forum (TMF).
For a Standard, you're going to need at least a foot - probably 2, just to have some in reserve. Kangaroo leather is the best for this purpose: thin, supple, and durable.
To get the length: if you have the original belt, measure that, then add a couple of inches for excess. Fit the belt leather over the pulleys, with the belt tensioner on the outside. Draw the belt just comfortably snug - not too tight: the tensioner takes care of that.
Mark where it meets the other end, then add about 3/8 - 1/2 inch for overlap. Cut to that length. Now take a NEW single edge razor blade, and carefully thin down both ends of the overlap: one end on the outside, and the other on the inside : this makes a smoother joint.
Coat both shaved-down ends with a thin coat of contact cement, and let them dry for a few minutes. Then re-thread the new belt around the pulleys, and press both ends together.
Once you're sure the cement is holding, you can take it off the pulley, and squeeze the joint with pliers to smooth it out; then put it back on the pulleys. You should be good to go.
The best tension for the belt should be just enough to turn the mandrel while playing, without slipping. If the belt is too loose, you can cut it apart, remove a tiny bit, and connect it again as above. If it's a little too tight, you can stretch the belt slightly by hand until it works properly.
I hope this has been useful to you.
Last Edit: Apr 14, 2015 23:08:27 GMT -5 by lucius1958
On a Model B Standard, I measured the old belt as 285mm (11.22in). I cut the new one to 290mm (11.42in), thus allowing 5mm or about 0.2in for the tapered overlap. This seems to have given a good result, and there is still plenty of room for the tensioner-arm to move so as to take up any slack that may develop if the belt stretches over the years. I presume that on a Model A Standard, with the motor screwed directly to the underside of the top plate rather than suspended on spring-loaded bolts, the belt length would be somewhat less, but to my shame I did not keep a record of the dimensions when changing the belt on a Model A many years ago.
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